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Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering
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Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering

Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering

The Ogemray SW40 (SKU: Ogemray-25A) is a 25A WiFi smart relay with built-in power metering, made by Ogemray Technology and imported by Shelly Europe as part of the “Powered By Shelly” programme. It is the recommended immersion heater control switch for Eleven Energy / Volta battery and solar systems: configured via the Eleven Energy app, it automatically diverts surplus solar generation into the immersion heater once the battery reaches its target state of charge — turning free electricity into hot water at no additional cost. Beyond the Eleven Energy ecosystem, the Ogemray SW40 is a fully-featured smart relay compatible with any home WiFi and the complete Shelly ecosystem: Home Assistant, Google Home, Amazon Alexa, Samsung SmartThings, MQTT, KNXnet/IP and 200+ other platforms. No hub required. Operates completely locally without internet connection. WiFi 2.4 GHz + Bluetooth 4.2. Dimensions: 60 × 52.4 × 24 mm. Wall-mount anchors and bracket included.

25A 6kW
Max load
Power Meter
Real-time
No hub
WiFi direct
Local first
No cloud needed
200+
Platform integrations
25A Scripts
mJs scripting
⚠ Installation by a competent person required: The Ogemray SW40 is a mains-voltage device switching up to 25A. All wiring must be carried out by a suitably qualified electrician in accordance with BS 7671 18th Edition wiring regulations. Appropriate isolation, fusing and protection devices must be in place before connection. Do not connect loads exceeding 25A / 6,000W. The device is rated for indoor use only.
ℹ Eleven Energy ecosystem — this device also works standalone with any WiFi network: This listing is optimised for the Eleven Energy / Volta solar battery ecosystem, where the Ogemray SW40 acts as a solar divert switch controlled via the Eleven Energy app. However, the underlying device is a full Shelly “Powered By Shelly” product: it connects to any home WiFi network and is fully compatible with the Shelly Cloud app, Home Assistant, Google Home, Amazon Alexa, Samsung SmartThings and 200+ other platforms. It operates completely locally without cloud access.
The solar divert case: why heating water with surplus solar is free money
A typical UK solar PV system generates more power than the household uses on summer afternoons. Without a smart divert switch, this excess is exported to the grid at the SEG rate (typically 3 – 15p/kWh). With an Ogemray SW40 in solar divert mode, once the Volta battery reaches its target SoC, the Eleven Energy app commands the SW40 to switch on the immersion heater. A 3 kW immersion running for 2 hours on surplus solar uses 6 kWh of otherwise-exported electricity — worth approximately £1.50 at 25p/kWh if it had been bought from the grid. Over a year, a well-configured solar divert system on a typical UK home can provide free hot water for 6 – 8 months, reducing or eliminating immersion heater electricity costs.
How the Ogemray SW40 Works as a Solar Divert Switch
1
Wire the SW40 between the consumer unit and the immersion heater
Connect the supply live and neutral, and the immersion circuit live and neutral to the device. Use the switched live terminal to feed the immersion heater. All wiring by a qualified electrician; appropriate fusing required.
2
Pair with the Eleven Energy app via Bluetooth
Open the Eleven Energy app, add the SW40 as a device. Bluetooth connectivity (range up to 10m indoors) makes pairing fast and simple without needing to configure WiFi credentials manually first.
3
Configure the solar divert automation
In the Eleven Energy app, set the automation rule: when the Volta battery state of charge reaches the target level (e.g. 95 %), and solar generation exceeds household demand, switch on the immersion heater.
4
The switch operates automatically from that point
The Ogemray SW40’s power meter confirms the immersion is drawing power. When solar generation drops (cloud cover, evening), the Eleven Energy app commands the switch off. Built-in overpower protection provides a safety backup.
5
Monitor energy usage in the app
The built-in power meter logs real-time and historical consumption. See exactly how many kWh have been diverted into the immersion in daily, weekly and monthly views.

Without Eleven Energy: the same automation logic can be built independently using the Shelly Cloud app, Home Assistant, or any MQTT/webhook-capable automation platform.

Key Features
25A / 6kW Rating — Handles Any UK Domestic Immersion or Resistive Load
The SW40 is rated for 25A continuous switching at 240V AC, giving a maximum load of 6,000W. Standard UK immersion heaters draw 3 kW on a 13 A circuit. The SW40’s 25A rating means it has a substantial safety margin for a 3 kW immersion (12 A draw vs 25 A rated), and is also suitable for larger 6 kW dual-element immersions (25 A), electric panel heaters, radiant floor heating elements, and other resistive loads within the rating. The relay is a single switched output — not a potential-free (dry contact) relay — so it switches the live supply directly. Large terminals accommodate the heavy-gauge cable appropriate for 25A circuits.
25A continuous240V AC6,000W maxLarge terminals
Built-In Power Metering — Voltage, Current, Power and Energy
The Ogemray SW40 monitors the connected load in real time: voltage, current draw, instantaneous power (W) and cumulative energy (kWh). For solar divert applications, this serves two purposes: (1) confirming the immersion is actually drawing power after the switch closes (not just the switch being on), and (2) tracking how many kWh have been diverted from surplus solar into the hot water tank over time. Historical data is stored in the Shelly Cloud and Eleven Energy app for daily, weekly and monthly energy analysis.
Voltage, current, power, energyReal-time monitoringCloud history
No Hub Required — Fully Local Operation, WiFi + Bluetooth
The SW40 connects directly to your home WiFi network at 2.4 GHz (802.11 b/g/n) — no Shelly Hub, Zigbee gateway or proprietary bridge needed. Bluetooth 4.2 (range up to 10 m indoors) is used for initial pairing and direct local control. Critically, the device has a built-in web server: all primary functions — switching, scheduling, automation rules, scripting — operate entirely locally on the device, regardless of whether the internet or Shelly Cloud is available. Schedules and automations programmed into the device continue to run even if your broadband connection goes down.
No hub requiredWiFi 2.4 GHz directBluetooth 4.2 setup100 % local operation
Overvoltage, Overcurrent, Overpower + Internal Temperature Protection
Four hardware protection mechanisms protect against fault conditions: overvoltage protection trips if the supply voltage exceeds safe limits; overcurrent protection opens the relay if current exceeds the set threshold; overpower protection cuts the load if wattage exceeds the configured limit (configurable in the app); and an internal temperature sensor triggers automatic shutdown if the device overheats. These protections can also trigger notifications or webhooks via the app, allowing fault alerts to be sent without manual monitoring.
OvervoltageOvercurrentOverpowerThermal cutoff
Full Shelly Ecosystem — Home Assistant, MQTT, Scripting, 200+ Integrations
As a “Powered By Shelly” device, the SW40 has the complete Shelly feature set: MQTT (standard IoT messaging protocol), webhooks (up to 20 with 5 URLs each), UDP, KNXnet/IP (building automation), Modbus, and mJs scripting for custom local automation logic. It integrates with Home Assistant natively (ideal for combining with solar inverter data for custom divert logic), Google Home, Amazon Alexa, Samsung SmartThings, Athom Homey, and 200+ additional partner platforms. Up to 20 schedules can be programmed directly into the device.
Home AssistantMQTT + KNXnet/IPmJs scripting20 schedules
Eleven Energy App Integration — Solar Divert, Battery SoC Triggers
For Eleven Energy (Volta) systems, the Ogemray SW40 is configured through the Eleven Energy app rather than — or in addition to — the standard Shelly Cloud app. Bluetooth onboarding connects the device to the Eleven ecosystem quickly. The automation capabilities include: solar divert (switch on when surplus PV power is available), battery SoC triggers (only divert once battery is above threshold), scheduled immersion heating (e.g. Economy 7 or Octopus Go off-peak periods), and coordination with other Eleven Energy/Volta devices for whole-home energy optimisation.
Eleven Energy appSolar divert triggerBattery SoC automationOff-peak scheduling
Compact 60 × 52.4 × 24 mm — Wall-Mount Anchors and Bracket Included
At just 60 × 52.4 × 24 mm, the SW40 fits inside a standard 35mm back-box / pattress box near the immersion heater or consumer unit. Wall-mount anchors and a bracket are supplied in the box for surface mounting without a back-box where appropriate. The compact size means it can also be installed inside a suitable enclosure adjacent to an existing consumer unit or fused spur. Device self-consumption is under 1.2W at idle.
60 × 52.4 × 24 mmWall-mount anchors included<1.2W self-consumption
Wiring Overview (Qualified Electrician Only)
⚠ All wiring must be by a suitably qualified electrician. The following is a conceptual overview only. Refer to the official Ogemray SW40 user manual for the wiring diagram. Ensure all circuits are de-energised and isolated before any wiring work. A dedicated fused spur rated for the load is required. The SW40 is not suitable for motor loads — use it with resistive loads only (immersion heaters, panel heaters).

The Ogemray SW40 is wired in-line on the immersion heater circuit. It has supply side terminals (live in, neutral in) and load side terminals (switched live out, neutral out). The switched live out feeds the immersion heater’s live terminal. Neutral is passed through unswitched. Typical installation for a 3 kW immersion on a dedicated 13 A circuit:

1. Isolate the immersion heater circuit at the consumer unit fuse/MCB.
2. Install the SW40 inside an appropriate enclosure near the immersion or CU, secured with the supplied wall-mount bracket.
3. Connect the incoming live (from CU) to the L-in terminal; incoming neutral to N-in terminal.
4. Connect the outgoing switched live (to immersion heater) from the L-out terminal; outgoing neutral to N-out terminal.
5. Ensure earth continuity is maintained on the circuit (not through the SW40).
6. Restore power and pair with the Eleven Energy or Shelly Cloud app via Bluetooth.

Full wiring diagram is in the Ogemray SW40 user manual (also available via shelly.link/Ogemray25A).

Technical Specifications
Product Identity
Full model name Ogemray SW40 PbS (Powered By Shelly)
Manufacturer Shenzhen Ogemray Technology Co., Ltd.
Imported by Shelly Europe Ltd., Sofia, Bulgaria
Electrical
Power supply 110 – 240 V AC ±10 %, 50/60 Hz
Max switching voltage 240 V AC
Max switching current 25 A
Max switching power 6,000 W
Device self-consumption <1.2 W
Channels 1 (single switched output)
Relay type Switched output — not potential-free / dry contact
Measurements and Protection
Power measurement Yes — voltage, current, power (W), energy (kWh)
Overvoltage protection Yes
Overcurrent protection Yes
Overpower protection Yes (configurable threshold)
Internal temperature sensor Yes — auto cutoff on overtemperature
Connectivity
WiFi 2.4 GHz 802.11 b/g/n · RF < 20 dBm
WiFi range Up to 50 m outdoors / 30 m indoors (environment dependent)
Bluetooth 4.2 · RF < 4 dBm
Bluetooth range Up to 30 m outdoors / 10 m indoors
Hub required No — direct WiFi connection
Automation and Integration
Schedules Up to 20
Webhooks Up to 20 (5 URLs per hook)
MQTT Yes (with TLS)
UDP Yes
KNXnet/IP Supported
Modbus Yes
Scripting Yes — mJs (micro-JavaScript)
HTTP / WebSocket Yes (with TLS)
Shelly Cloud app iOS and Android — remote monitoring and control
Local web interface Yes — at device IP or 192.168.33.1 via access point
Third-party integrations 200+ platforms: Home Assistant, Google Home, Alexa, SmartThings, Homey etc.
Eleven Energy app Yes — solar divert, battery SoC triggers, scheduling
Physical
Dimensions (H × W × L) 60 × 52.4 × 24 mm
Mounting Wall-mount anchors and bracket included
Environmental
Operating temperature −20°C to +40°C
Operating humidity 30 – 70 % RH
Environment Indoor use only
Compliance
Directives RED 2014/53/EU · LVD 2014/35/EU · EMC 2014/30/EU · RoHS 2011/65/EU
Frequently Asked Questions
Do I need an Eleven Energy system to use this switch?
No. The Ogemray SW40 is a full Shelly “Powered By Shelly” device that works with any home WiFi network. Without an Eleven Energy system, you can control it via the Shelly Cloud app (iOS/Android), use Home Assistant for advanced solar divert automation (integrating with your inverter’s data via Modbus or API), set fixed schedules for off-peak immersion heating, or create webhook/MQTT automations with any compatible platform. The Eleven Energy integration is an additional layer for customers who also have a Volta/Eleven Energy battery system.
Can I use this to control a 6kW dual-element immersion heater?
A dual-element 6kW immersion heater draws approximately 25A at 240V. The Ogemray SW40 is rated for exactly 25A, which means a 6kW dual-element immersion is at the device’s maximum rated current. This is within specification, but it is good practice to keep continuous loads below 80 % of a relay’s rated capacity for longevity. For a 6kW immersion running continuously for extended periods, a 32A-rated alternative may be more appropriate. For a standard single-element 3kW immersion (13A draw), the SW40 has substantial headroom and is an ideal match.
Does this work with Home Assistant for solar divert without Eleven Energy?
Yes. The Ogemray SW40 integrates with Home Assistant via the Shelly integration (available in HACS or as a standard integration). This exposes the switch state, power reading, energy data and control as entities in Home Assistant. You can then build automation in Home Assistant to divert solar: when PV generation exceeds household consumption by a threshold amount (read from your inverter’s Modbus or API), turn on the immersion switch. This approach is popular with installers using Solis, SolaX and other inverters that expose generation data via Modbus or local API.
Does it work without an internet connection?
Yes. The Ogemray SW40 has a built-in web server that provides all primary functions locally, including switching, schedules, automation rules and scripting. If your broadband connection goes down, schedules and programmed automations continue to run on the device. Remote access via the Shelly Cloud app or Eleven Energy app requires an internet connection, but local control via the device’s web interface at its IP address on the home network does not.
What load types can I control with the Ogemray SW40?
The Ogemray SW40 is suitable for resistive loads: immersion heaters, electric panel heaters, radiant floor heating elements, electric towel rails, resistive space heaters. It is not recommended for motor loads (pumps, compressors, fans) because motor starts cause current inrush that can damage relay contacts rated for resistive switching. It is also not suitable for dimming, phase-cut control of heating elements, or any load requiring a potential-free (dry contact) relay — the SW40 is a switched live output, not a volt-free contact.
How does the power metering help with solar divert optimisation?
The power meter lets you verify that the solar divert is working correctly and quantify the savings. With the switch in divert mode, you can confirm the immersion is drawing the expected 3 kW (not open-circuit or short-circuit), see cumulative kWh diverted into the hot water tank per day/week/month, and set overpower alerts if the immersion draws more than expected (which could indicate a wiring fault or element failure). Historical energy data in the Shelly Cloud and Eleven Energy app lets you calculate the carbon and cost value of the diverted solar energy.
$26.45

Original: $75.58

-65%
Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering—

$75.58

$26.45

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Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering - Image 2
Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering - Image 3
Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering - Image 4
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Shelly Ogemray SW40 25A Smart Switch Immersion Heater Control Solar Divert, WiFi, Bluetooth, Power Metering

The Ogemray SW40 (SKU: Ogemray-25A) is a 25A WiFi smart relay with built-in power metering, made by Ogemray Technology and imported by Shelly Europe as part of the “Powered By Shelly” programme. It is the recommended immersion heater control switch for Eleven Energy / Volta battery and solar systems: configured via the Eleven Energy app, it automatically diverts surplus solar generation into the immersion heater once the battery reaches its target state of charge — turning free electricity into hot water at no additional cost. Beyond the Eleven Energy ecosystem, the Ogemray SW40 is a fully-featured smart relay compatible with any home WiFi and the complete Shelly ecosystem: Home Assistant, Google Home, Amazon Alexa, Samsung SmartThings, MQTT, KNXnet/IP and 200+ other platforms. No hub required. Operates completely locally without internet connection. WiFi 2.4 GHz + Bluetooth 4.2. Dimensions: 60 × 52.4 × 24 mm. Wall-mount anchors and bracket included.

25A 6kW
Max load
Power Meter
Real-time
No hub
WiFi direct
Local first
No cloud needed
200+
Platform integrations
25A Scripts
mJs scripting
⚠ Installation by a competent person required: The Ogemray SW40 is a mains-voltage device switching up to 25A. All wiring must be carried out by a suitably qualified electrician in accordance with BS 7671 18th Edition wiring regulations. Appropriate isolation, fusing and protection devices must be in place before connection. Do not connect loads exceeding 25A / 6,000W. The device is rated for indoor use only.
ℹ Eleven Energy ecosystem — this device also works standalone with any WiFi network: This listing is optimised for the Eleven Energy / Volta solar battery ecosystem, where the Ogemray SW40 acts as a solar divert switch controlled via the Eleven Energy app. However, the underlying device is a full Shelly “Powered By Shelly” product: it connects to any home WiFi network and is fully compatible with the Shelly Cloud app, Home Assistant, Google Home, Amazon Alexa, Samsung SmartThings and 200+ other platforms. It operates completely locally without cloud access.
The solar divert case: why heating water with surplus solar is free money
A typical UK solar PV system generates more power than the household uses on summer afternoons. Without a smart divert switch, this excess is exported to the grid at the SEG rate (typically 3 – 15p/kWh). With an Ogemray SW40 in solar divert mode, once the Volta battery reaches its target SoC, the Eleven Energy app commands the SW40 to switch on the immersion heater. A 3 kW immersion running for 2 hours on surplus solar uses 6 kWh of otherwise-exported electricity — worth approximately £1.50 at 25p/kWh if it had been bought from the grid. Over a year, a well-configured solar divert system on a typical UK home can provide free hot water for 6 – 8 months, reducing or eliminating immersion heater electricity costs.
How the Ogemray SW40 Works as a Solar Divert Switch
1
Wire the SW40 between the consumer unit and the immersion heater
Connect the supply live and neutral, and the immersion circuit live and neutral to the device. Use the switched live terminal to feed the immersion heater. All wiring by a qualified electrician; appropriate fusing required.
2
Pair with the Eleven Energy app via Bluetooth
Open the Eleven Energy app, add the SW40 as a device. Bluetooth connectivity (range up to 10m indoors) makes pairing fast and simple without needing to configure WiFi credentials manually first.
3
Configure the solar divert automation
In the Eleven Energy app, set the automation rule: when the Volta battery state of charge reaches the target level (e.g. 95 %), and solar generation exceeds household demand, switch on the immersion heater.
4
The switch operates automatically from that point
The Ogemray SW40’s power meter confirms the immersion is drawing power. When solar generation drops (cloud cover, evening), the Eleven Energy app commands the switch off. Built-in overpower protection provides a safety backup.
5
Monitor energy usage in the app
The built-in power meter logs real-time and historical consumption. See exactly how many kWh have been diverted into the immersion in daily, weekly and monthly views.

Without Eleven Energy: the same automation logic can be built independently using the Shelly Cloud app, Home Assistant, or any MQTT/webhook-capable automation platform.

Key Features
25A / 6kW Rating — Handles Any UK Domestic Immersion or Resistive Load
The SW40 is rated for 25A continuous switching at 240V AC, giving a maximum load of 6,000W. Standard UK immersion heaters draw 3 kW on a 13 A circuit. The SW40’s 25A rating means it has a substantial safety margin for a 3 kW immersion (12 A draw vs 25 A rated), and is also suitable for larger 6 kW dual-element immersions (25 A), electric panel heaters, radiant floor heating elements, and other resistive loads within the rating. The relay is a single switched output — not a potential-free (dry contact) relay — so it switches the live supply directly. Large terminals accommodate the heavy-gauge cable appropriate for 25A circuits.
25A continuous240V AC6,000W maxLarge terminals
Built-In Power Metering — Voltage, Current, Power and Energy
The Ogemray SW40 monitors the connected load in real time: voltage, current draw, instantaneous power (W) and cumulative energy (kWh). For solar divert applications, this serves two purposes: (1) confirming the immersion is actually drawing power after the switch closes (not just the switch being on), and (2) tracking how many kWh have been diverted from surplus solar into the hot water tank over time. Historical data is stored in the Shelly Cloud and Eleven Energy app for daily, weekly and monthly energy analysis.
Voltage, current, power, energyReal-time monitoringCloud history
No Hub Required — Fully Local Operation, WiFi + Bluetooth
The SW40 connects directly to your home WiFi network at 2.4 GHz (802.11 b/g/n) — no Shelly Hub, Zigbee gateway or proprietary bridge needed. Bluetooth 4.2 (range up to 10 m indoors) is used for initial pairing and direct local control. Critically, the device has a built-in web server: all primary functions — switching, scheduling, automation rules, scripting — operate entirely locally on the device, regardless of whether the internet or Shelly Cloud is available. Schedules and automations programmed into the device continue to run even if your broadband connection goes down.
No hub requiredWiFi 2.4 GHz directBluetooth 4.2 setup100 % local operation
Overvoltage, Overcurrent, Overpower + Internal Temperature Protection
Four hardware protection mechanisms protect against fault conditions: overvoltage protection trips if the supply voltage exceeds safe limits; overcurrent protection opens the relay if current exceeds the set threshold; overpower protection cuts the load if wattage exceeds the configured limit (configurable in the app); and an internal temperature sensor triggers automatic shutdown if the device overheats. These protections can also trigger notifications or webhooks via the app, allowing fault alerts to be sent without manual monitoring.
OvervoltageOvercurrentOverpowerThermal cutoff
Full Shelly Ecosystem — Home Assistant, MQTT, Scripting, 200+ Integrations
As a “Powered By Shelly” device, the SW40 has the complete Shelly feature set: MQTT (standard IoT messaging protocol), webhooks (up to 20 with 5 URLs each), UDP, KNXnet/IP (building automation), Modbus, and mJs scripting for custom local automation logic. It integrates with Home Assistant natively (ideal for combining with solar inverter data for custom divert logic), Google Home, Amazon Alexa, Samsung SmartThings, Athom Homey, and 200+ additional partner platforms. Up to 20 schedules can be programmed directly into the device.
Home AssistantMQTT + KNXnet/IPmJs scripting20 schedules
Eleven Energy App Integration — Solar Divert, Battery SoC Triggers
For Eleven Energy (Volta) systems, the Ogemray SW40 is configured through the Eleven Energy app rather than — or in addition to — the standard Shelly Cloud app. Bluetooth onboarding connects the device to the Eleven ecosystem quickly. The automation capabilities include: solar divert (switch on when surplus PV power is available), battery SoC triggers (only divert once battery is above threshold), scheduled immersion heating (e.g. Economy 7 or Octopus Go off-peak periods), and coordination with other Eleven Energy/Volta devices for whole-home energy optimisation.
Eleven Energy appSolar divert triggerBattery SoC automationOff-peak scheduling
Compact 60 × 52.4 × 24 mm — Wall-Mount Anchors and Bracket Included
At just 60 × 52.4 × 24 mm, the SW40 fits inside a standard 35mm back-box / pattress box near the immersion heater or consumer unit. Wall-mount anchors and a bracket are supplied in the box for surface mounting without a back-box where appropriate. The compact size means it can also be installed inside a suitable enclosure adjacent to an existing consumer unit or fused spur. Device self-consumption is under 1.2W at idle.
60 × 52.4 × 24 mmWall-mount anchors included<1.2W self-consumption
Wiring Overview (Qualified Electrician Only)
⚠ All wiring must be by a suitably qualified electrician. The following is a conceptual overview only. Refer to the official Ogemray SW40 user manual for the wiring diagram. Ensure all circuits are de-energised and isolated before any wiring work. A dedicated fused spur rated for the load is required. The SW40 is not suitable for motor loads — use it with resistive loads only (immersion heaters, panel heaters).

The Ogemray SW40 is wired in-line on the immersion heater circuit. It has supply side terminals (live in, neutral in) and load side terminals (switched live out, neutral out). The switched live out feeds the immersion heater’s live terminal. Neutral is passed through unswitched. Typical installation for a 3 kW immersion on a dedicated 13 A circuit:

1. Isolate the immersion heater circuit at the consumer unit fuse/MCB.
2. Install the SW40 inside an appropriate enclosure near the immersion or CU, secured with the supplied wall-mount bracket.
3. Connect the incoming live (from CU) to the L-in terminal; incoming neutral to N-in terminal.
4. Connect the outgoing switched live (to immersion heater) from the L-out terminal; outgoing neutral to N-out terminal.
5. Ensure earth continuity is maintained on the circuit (not through the SW40).
6. Restore power and pair with the Eleven Energy or Shelly Cloud app via Bluetooth.

Full wiring diagram is in the Ogemray SW40 user manual (also available via shelly.link/Ogemray25A).

Technical Specifications
Product Identity
Full model name Ogemray SW40 PbS (Powered By Shelly)
Manufacturer Shenzhen Ogemray Technology Co., Ltd.
Imported by Shelly Europe Ltd., Sofia, Bulgaria
Electrical
Power supply 110 – 240 V AC ±10 %, 50/60 Hz
Max switching voltage 240 V AC
Max switching current 25 A
Max switching power 6,000 W
Device self-consumption <1.2 W
Channels 1 (single switched output)
Relay type Switched output — not potential-free / dry contact
Measurements and Protection
Power measurement Yes — voltage, current, power (W), energy (kWh)
Overvoltage protection Yes
Overcurrent protection Yes
Overpower protection Yes (configurable threshold)
Internal temperature sensor Yes — auto cutoff on overtemperature
Connectivity
WiFi 2.4 GHz 802.11 b/g/n · RF < 20 dBm
WiFi range Up to 50 m outdoors / 30 m indoors (environment dependent)
Bluetooth 4.2 · RF < 4 dBm
Bluetooth range Up to 30 m outdoors / 10 m indoors
Hub required No — direct WiFi connection
Automation and Integration
Schedules Up to 20
Webhooks Up to 20 (5 URLs per hook)
MQTT Yes (with TLS)
UDP Yes
KNXnet/IP Supported
Modbus Yes
Scripting Yes — mJs (micro-JavaScript)
HTTP / WebSocket Yes (with TLS)
Shelly Cloud app iOS and Android — remote monitoring and control
Local web interface Yes — at device IP or 192.168.33.1 via access point
Third-party integrations 200+ platforms: Home Assistant, Google Home, Alexa, SmartThings, Homey etc.
Eleven Energy app Yes — solar divert, battery SoC triggers, scheduling
Physical
Dimensions (H × W × L) 60 × 52.4 × 24 mm
Mounting Wall-mount anchors and bracket included
Environmental
Operating temperature −20°C to +40°C
Operating humidity 30 – 70 % RH
Environment Indoor use only
Compliance
Directives RED 2014/53/EU · LVD 2014/35/EU · EMC 2014/30/EU · RoHS 2011/65/EU
Frequently Asked Questions
Do I need an Eleven Energy system to use this switch?
No. The Ogemray SW40 is a full Shelly “Powered By Shelly” device that works with any home WiFi network. Without an Eleven Energy system, you can control it via the Shelly Cloud app (iOS/Android), use Home Assistant for advanced solar divert automation (integrating with your inverter’s data via Modbus or API), set fixed schedules for off-peak immersion heating, or create webhook/MQTT automations with any compatible platform. The Eleven Energy integration is an additional layer for customers who also have a Volta/Eleven Energy battery system.
Can I use this to control a 6kW dual-element immersion heater?
A dual-element 6kW immersion heater draws approximately 25A at 240V. The Ogemray SW40 is rated for exactly 25A, which means a 6kW dual-element immersion is at the device’s maximum rated current. This is within specification, but it is good practice to keep continuous loads below 80 % of a relay’s rated capacity for longevity. For a 6kW immersion running continuously for extended periods, a 32A-rated alternative may be more appropriate. For a standard single-element 3kW immersion (13A draw), the SW40 has substantial headroom and is an ideal match.
Does this work with Home Assistant for solar divert without Eleven Energy?
Yes. The Ogemray SW40 integrates with Home Assistant via the Shelly integration (available in HACS or as a standard integration). This exposes the switch state, power reading, energy data and control as entities in Home Assistant. You can then build automation in Home Assistant to divert solar: when PV generation exceeds household consumption by a threshold amount (read from your inverter’s Modbus or API), turn on the immersion switch. This approach is popular with installers using Solis, SolaX and other inverters that expose generation data via Modbus or local API.
Does it work without an internet connection?
Yes. The Ogemray SW40 has a built-in web server that provides all primary functions locally, including switching, schedules, automation rules and scripting. If your broadband connection goes down, schedules and programmed automations continue to run on the device. Remote access via the Shelly Cloud app or Eleven Energy app requires an internet connection, but local control via the device’s web interface at its IP address on the home network does not.
What load types can I control with the Ogemray SW40?
The Ogemray SW40 is suitable for resistive loads: immersion heaters, electric panel heaters, radiant floor heating elements, electric towel rails, resistive space heaters. It is not recommended for motor loads (pumps, compressors, fans) because motor starts cause current inrush that can damage relay contacts rated for resistive switching. It is also not suitable for dimming, phase-cut control of heating elements, or any load requiring a potential-free (dry contact) relay — the SW40 is a switched live output, not a volt-free contact.
How does the power metering help with solar divert optimisation?
The power meter lets you verify that the solar divert is working correctly and quantify the savings. With the switch in divert mode, you can confirm the immersion is drawing the expected 3 kW (not open-circuit or short-circuit), see cumulative kWh diverted into the hot water tank per day/week/month, and set overpower alerts if the immersion draws more than expected (which could indicate a wiring fault or element failure). Historical energy data in the Shelly Cloud and Eleven Energy app lets you calculate the carbon and cost value of the diverted solar energy.

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Description

The Ogemray SW40 (SKU: Ogemray-25A) is a 25A WiFi smart relay with built-in power metering, made by Ogemray Technology and imported by Shelly Europe as part of the “Powered By Shelly” programme. It is the recommended immersion heater control switch for Eleven Energy / Volta battery and solar systems: configured via the Eleven Energy app, it automatically diverts surplus solar generation into the immersion heater once the battery reaches its target state of charge — turning free electricity into hot water at no additional cost. Beyond the Eleven Energy ecosystem, the Ogemray SW40 is a fully-featured smart relay compatible with any home WiFi and the complete Shelly ecosystem: Home Assistant, Google Home, Amazon Alexa, Samsung SmartThings, MQTT, KNXnet/IP and 200+ other platforms. No hub required. Operates completely locally without internet connection. WiFi 2.4 GHz + Bluetooth 4.2. Dimensions: 60 × 52.4 × 24 mm. Wall-mount anchors and bracket included.

25A 6kW
Max load
Power Meter
Real-time
No hub
WiFi direct
Local first
No cloud needed
200+
Platform integrations
25A Scripts
mJs scripting
⚠ Installation by a competent person required: The Ogemray SW40 is a mains-voltage device switching up to 25A. All wiring must be carried out by a suitably qualified electrician in accordance with BS 7671 18th Edition wiring regulations. Appropriate isolation, fusing and protection devices must be in place before connection. Do not connect loads exceeding 25A / 6,000W. The device is rated for indoor use only.
ℹ Eleven Energy ecosystem — this device also works standalone with any WiFi network: This listing is optimised for the Eleven Energy / Volta solar battery ecosystem, where the Ogemray SW40 acts as a solar divert switch controlled via the Eleven Energy app. However, the underlying device is a full Shelly “Powered By Shelly” product: it connects to any home WiFi network and is fully compatible with the Shelly Cloud app, Home Assistant, Google Home, Amazon Alexa, Samsung SmartThings and 200+ other platforms. It operates completely locally without cloud access.
The solar divert case: why heating water with surplus solar is free money
A typical UK solar PV system generates more power than the household uses on summer afternoons. Without a smart divert switch, this excess is exported to the grid at the SEG rate (typically 3 – 15p/kWh). With an Ogemray SW40 in solar divert mode, once the Volta battery reaches its target SoC, the Eleven Energy app commands the SW40 to switch on the immersion heater. A 3 kW immersion running for 2 hours on surplus solar uses 6 kWh of otherwise-exported electricity — worth approximately £1.50 at 25p/kWh if it had been bought from the grid. Over a year, a well-configured solar divert system on a typical UK home can provide free hot water for 6 – 8 months, reducing or eliminating immersion heater electricity costs.
How the Ogemray SW40 Works as a Solar Divert Switch
1
Wire the SW40 between the consumer unit and the immersion heater
Connect the supply live and neutral, and the immersion circuit live and neutral to the device. Use the switched live terminal to feed the immersion heater. All wiring by a qualified electrician; appropriate fusing required.
2
Pair with the Eleven Energy app via Bluetooth
Open the Eleven Energy app, add the SW40 as a device. Bluetooth connectivity (range up to 10m indoors) makes pairing fast and simple without needing to configure WiFi credentials manually first.
3
Configure the solar divert automation
In the Eleven Energy app, set the automation rule: when the Volta battery state of charge reaches the target level (e.g. 95 %), and solar generation exceeds household demand, switch on the immersion heater.
4
The switch operates automatically from that point
The Ogemray SW40’s power meter confirms the immersion is drawing power. When solar generation drops (cloud cover, evening), the Eleven Energy app commands the switch off. Built-in overpower protection provides a safety backup.
5
Monitor energy usage in the app
The built-in power meter logs real-time and historical consumption. See exactly how many kWh have been diverted into the immersion in daily, weekly and monthly views.

Without Eleven Energy: the same automation logic can be built independently using the Shelly Cloud app, Home Assistant, or any MQTT/webhook-capable automation platform.

Key Features
25A / 6kW Rating — Handles Any UK Domestic Immersion or Resistive Load
The SW40 is rated for 25A continuous switching at 240V AC, giving a maximum load of 6,000W. Standard UK immersion heaters draw 3 kW on a 13 A circuit. The SW40’s 25A rating means it has a substantial safety margin for a 3 kW immersion (12 A draw vs 25 A rated), and is also suitable for larger 6 kW dual-element immersions (25 A), electric panel heaters, radiant floor heating elements, and other resistive loads within the rating. The relay is a single switched output — not a potential-free (dry contact) relay — so it switches the live supply directly. Large terminals accommodate the heavy-gauge cable appropriate for 25A circuits.
25A continuous240V AC6,000W maxLarge terminals
Built-In Power Metering — Voltage, Current, Power and Energy
The Ogemray SW40 monitors the connected load in real time: voltage, current draw, instantaneous power (W) and cumulative energy (kWh). For solar divert applications, this serves two purposes: (1) confirming the immersion is actually drawing power after the switch closes (not just the switch being on), and (2) tracking how many kWh have been diverted from surplus solar into the hot water tank over time. Historical data is stored in the Shelly Cloud and Eleven Energy app for daily, weekly and monthly energy analysis.
Voltage, current, power, energyReal-time monitoringCloud history
No Hub Required — Fully Local Operation, WiFi + Bluetooth
The SW40 connects directly to your home WiFi network at 2.4 GHz (802.11 b/g/n) — no Shelly Hub, Zigbee gateway or proprietary bridge needed. Bluetooth 4.2 (range up to 10 m indoors) is used for initial pairing and direct local control. Critically, the device has a built-in web server: all primary functions — switching, scheduling, automation rules, scripting — operate entirely locally on the device, regardless of whether the internet or Shelly Cloud is available. Schedules and automations programmed into the device continue to run even if your broadband connection goes down.
No hub requiredWiFi 2.4 GHz directBluetooth 4.2 setup100 % local operation
Overvoltage, Overcurrent, Overpower + Internal Temperature Protection
Four hardware protection mechanisms protect against fault conditions: overvoltage protection trips if the supply voltage exceeds safe limits; overcurrent protection opens the relay if current exceeds the set threshold; overpower protection cuts the load if wattage exceeds the configured limit (configurable in the app); and an internal temperature sensor triggers automatic shutdown if the device overheats. These protections can also trigger notifications or webhooks via the app, allowing fault alerts to be sent without manual monitoring.
OvervoltageOvercurrentOverpowerThermal cutoff
Full Shelly Ecosystem — Home Assistant, MQTT, Scripting, 200+ Integrations
As a “Powered By Shelly” device, the SW40 has the complete Shelly feature set: MQTT (standard IoT messaging protocol), webhooks (up to 20 with 5 URLs each), UDP, KNXnet/IP (building automation), Modbus, and mJs scripting for custom local automation logic. It integrates with Home Assistant natively (ideal for combining with solar inverter data for custom divert logic), Google Home, Amazon Alexa, Samsung SmartThings, Athom Homey, and 200+ additional partner platforms. Up to 20 schedules can be programmed directly into the device.
Home AssistantMQTT + KNXnet/IPmJs scripting20 schedules
Eleven Energy App Integration — Solar Divert, Battery SoC Triggers
For Eleven Energy (Volta) systems, the Ogemray SW40 is configured through the Eleven Energy app rather than — or in addition to — the standard Shelly Cloud app. Bluetooth onboarding connects the device to the Eleven ecosystem quickly. The automation capabilities include: solar divert (switch on when surplus PV power is available), battery SoC triggers (only divert once battery is above threshold), scheduled immersion heating (e.g. Economy 7 or Octopus Go off-peak periods), and coordination with other Eleven Energy/Volta devices for whole-home energy optimisation.
Eleven Energy appSolar divert triggerBattery SoC automationOff-peak scheduling
Compact 60 × 52.4 × 24 mm — Wall-Mount Anchors and Bracket Included
At just 60 × 52.4 × 24 mm, the SW40 fits inside a standard 35mm back-box / pattress box near the immersion heater or consumer unit. Wall-mount anchors and a bracket are supplied in the box for surface mounting without a back-box where appropriate. The compact size means it can also be installed inside a suitable enclosure adjacent to an existing consumer unit or fused spur. Device self-consumption is under 1.2W at idle.
60 × 52.4 × 24 mmWall-mount anchors included<1.2W self-consumption
Wiring Overview (Qualified Electrician Only)
⚠ All wiring must be by a suitably qualified electrician. The following is a conceptual overview only. Refer to the official Ogemray SW40 user manual for the wiring diagram. Ensure all circuits are de-energised and isolated before any wiring work. A dedicated fused spur rated for the load is required. The SW40 is not suitable for motor loads — use it with resistive loads only (immersion heaters, panel heaters).

The Ogemray SW40 is wired in-line on the immersion heater circuit. It has supply side terminals (live in, neutral in) and load side terminals (switched live out, neutral out). The switched live out feeds the immersion heater’s live terminal. Neutral is passed through unswitched. Typical installation for a 3 kW immersion on a dedicated 13 A circuit:

1. Isolate the immersion heater circuit at the consumer unit fuse/MCB.
2. Install the SW40 inside an appropriate enclosure near the immersion or CU, secured with the supplied wall-mount bracket.
3. Connect the incoming live (from CU) to the L-in terminal; incoming neutral to N-in terminal.
4. Connect the outgoing switched live (to immersion heater) from the L-out terminal; outgoing neutral to N-out terminal.
5. Ensure earth continuity is maintained on the circuit (not through the SW40).
6. Restore power and pair with the Eleven Energy or Shelly Cloud app via Bluetooth.

Full wiring diagram is in the Ogemray SW40 user manual (also available via shelly.link/Ogemray25A).

Technical Specifications
Product Identity
Full model name Ogemray SW40 PbS (Powered By Shelly)
Manufacturer Shenzhen Ogemray Technology Co., Ltd.
Imported by Shelly Europe Ltd., Sofia, Bulgaria
Electrical
Power supply 110 – 240 V AC ±10 %, 50/60 Hz
Max switching voltage 240 V AC
Max switching current 25 A
Max switching power 6,000 W
Device self-consumption <1.2 W
Channels 1 (single switched output)
Relay type Switched output — not potential-free / dry contact
Measurements and Protection
Power measurement Yes — voltage, current, power (W), energy (kWh)
Overvoltage protection Yes
Overcurrent protection Yes
Overpower protection Yes (configurable threshold)
Internal temperature sensor Yes — auto cutoff on overtemperature
Connectivity
WiFi 2.4 GHz 802.11 b/g/n · RF < 20 dBm
WiFi range Up to 50 m outdoors / 30 m indoors (environment dependent)
Bluetooth 4.2 · RF < 4 dBm
Bluetooth range Up to 30 m outdoors / 10 m indoors
Hub required No — direct WiFi connection
Automation and Integration
Schedules Up to 20
Webhooks Up to 20 (5 URLs per hook)
MQTT Yes (with TLS)
UDP Yes
KNXnet/IP Supported
Modbus Yes
Scripting Yes — mJs (micro-JavaScript)
HTTP / WebSocket Yes (with TLS)
Shelly Cloud app iOS and Android — remote monitoring and control
Local web interface Yes — at device IP or 192.168.33.1 via access point
Third-party integrations 200+ platforms: Home Assistant, Google Home, Alexa, SmartThings, Homey etc.
Eleven Energy app Yes — solar divert, battery SoC triggers, scheduling
Physical
Dimensions (H × W × L) 60 × 52.4 × 24 mm
Mounting Wall-mount anchors and bracket included
Environmental
Operating temperature −20°C to +40°C
Operating humidity 30 – 70 % RH
Environment Indoor use only
Compliance
Directives RED 2014/53/EU · LVD 2014/35/EU · EMC 2014/30/EU · RoHS 2011/65/EU
Frequently Asked Questions
Do I need an Eleven Energy system to use this switch?
No. The Ogemray SW40 is a full Shelly “Powered By Shelly” device that works with any home WiFi network. Without an Eleven Energy system, you can control it via the Shelly Cloud app (iOS/Android), use Home Assistant for advanced solar divert automation (integrating with your inverter’s data via Modbus or API), set fixed schedules for off-peak immersion heating, or create webhook/MQTT automations with any compatible platform. The Eleven Energy integration is an additional layer for customers who also have a Volta/Eleven Energy battery system.
Can I use this to control a 6kW dual-element immersion heater?
A dual-element 6kW immersion heater draws approximately 25A at 240V. The Ogemray SW40 is rated for exactly 25A, which means a 6kW dual-element immersion is at the device’s maximum rated current. This is within specification, but it is good practice to keep continuous loads below 80 % of a relay’s rated capacity for longevity. For a 6kW immersion running continuously for extended periods, a 32A-rated alternative may be more appropriate. For a standard single-element 3kW immersion (13A draw), the SW40 has substantial headroom and is an ideal match.
Does this work with Home Assistant for solar divert without Eleven Energy?
Yes. The Ogemray SW40 integrates with Home Assistant via the Shelly integration (available in HACS or as a standard integration). This exposes the switch state, power reading, energy data and control as entities in Home Assistant. You can then build automation in Home Assistant to divert solar: when PV generation exceeds household consumption by a threshold amount (read from your inverter’s Modbus or API), turn on the immersion switch. This approach is popular with installers using Solis, SolaX and other inverters that expose generation data via Modbus or local API.
Does it work without an internet connection?
Yes. The Ogemray SW40 has a built-in web server that provides all primary functions locally, including switching, schedules, automation rules and scripting. If your broadband connection goes down, schedules and programmed automations continue to run on the device. Remote access via the Shelly Cloud app or Eleven Energy app requires an internet connection, but local control via the device’s web interface at its IP address on the home network does not.
What load types can I control with the Ogemray SW40?
The Ogemray SW40 is suitable for resistive loads: immersion heaters, electric panel heaters, radiant floor heating elements, electric towel rails, resistive space heaters. It is not recommended for motor loads (pumps, compressors, fans) because motor starts cause current inrush that can damage relay contacts rated for resistive switching. It is also not suitable for dimming, phase-cut control of heating elements, or any load requiring a potential-free (dry contact) relay — the SW40 is a switched live output, not a volt-free contact.
How does the power metering help with solar divert optimisation?
The power meter lets you verify that the solar divert is working correctly and quantify the savings. With the switch in divert mode, you can confirm the immersion is drawing the expected 3 kW (not open-circuit or short-circuit), see cumulative kWh diverted into the hot water tank per day/week/month, and set overpower alerts if the immersion draws more than expected (which could indicate a wiring fault or element failure). Historical energy data in the Shelly Cloud and Eleven Energy app lets you calculate the carbon and cost value of the diverted solar energy.